Objectives To analyse the value of the anti-cyclic citrullinated peptide antibody (anti-CCP) inpatients with rheumatoid arthritis (RA) as a prognostic factor as well as its relationship with disease activity. Methods A cross-sectional study was made on 89 patients with RA. The following values were assessed: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-CCP Disease A ctivily Score 28 (DAS 28), Modified Health Assessment Questionnaire score (M-HAQ) and simplified radiologic score of Sharp/Van der Heijde (SENS: simple erosion narrowing score). Results Sixty-four percent of the patients were anti-CCP positive, from which 36.8% were negative for RE Among negative RF patients, 48.3% had anti-CCP antibody. The average value of DAS 28 in anti-CCP positive patients was 4.31 (SD 1.27) compared to 3.30 (SD 1.55)for anti-CCP negative (p <= 0.001). There was a significant correlation between anti-CCP levels and CRP value (p <= 0.011). 78.9% of anti-CCP positive patients presented erosions as opposed to a 53.1% of those with negative anti-CCP (p <= 0.011), OR 3.3 (95% CI: 1.3-8.5). SENS in anti-CCP positive patients was significantly greater than in anti-CCP negative patients, 22.6 (SD 20.7) versus 13.88 (SD 19.24) (p <= 0.054). Patients with high levels of anti-CCP (> 200 U/ml) had higher SENS (p < 0.05). There was no correlation between M-HAQ and anti-CCP. Conclusions Prevalence of anti-CCP was higher among patients with higher activity. Patients with higher levels of anti-CCP antibody had more aggressive disease, with greater activity (elevated values in DAS 28 and CRP) and more severe radiological damage (more erosions and higher radiological damage, SENS).